<template>
	<view>
		<!-- 使用自定义的搜索组件 -->
			<Mysearch @click="gotoSearch"></Mysearch>
		<view class="scroll-view-container">
			<!-- 左侧滑动 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
				<block v-for="(item,i) in cateList" :key="i">
					<view :class="['left-scroll-view-item',i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
				</block>
			</scroll-view>
			<!-- 右侧的滚动视图区域 -->
			<scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrolltop">
			  <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
			    <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
			    <!-- 动态渲染三级分类的列表数据 -->
			    <view class="cate-lv3-list">
			      <!-- 三级分类 Item 项 -->
			      <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
			        <!-- 图片 -->
			        <image :src="item3.cat_icon"></image>
			        <!-- 文本 -->
			        <text>{{item3.cat_name}}</text>
			      </view>
			    </view>
			  </view>
			</scroll-view>
		</view>
		
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tabbar-badge.js'
	export default {
		mixins:[badgeMix],
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh: 0,
				// 分类数据列表
				cateList:[],
				active:0,
				//二级分类列表
				cateLevel2:[],
				// 滚动条距离顶部的距离
				scrolltop:0
			};
		},
		onLoad() {
		      // 获取当前系统的信息
		      const sysInfo = uni.getSystemInfoSync()
		      // 为 wh 窗口可用高度动态赋值
		      this.wh = sysInfo.windowHeight - 50
			  // 调用获取分类列表数据的方法
				this.getCateList()
		    },
			methods:{
				async getCateList(){
					const {data:res} = await uni.$http.get('/api/public/v1/categories')
					if(res.meta.status !== 200 ) return uni.$showMsg()
					this.cateList = res.message
					//为二级分类赋值
					this.cateLevel2 = res.message[0].children
				},
				activeChanged(i){
					this.active = i
					// 为二级分类列表重新赋值
					this.cateLevel2 = this.cateList[i].children
					//为滚动条的值重新赋值
					this.scrolltop = this.scrolltop === 0 ? 1:0
				},
				//跳转页面并传参
				gotoGoodsList(item3){
					uni.navigateTo({
						url:'/subpkg/goods_list/goods_list?cid=' + item3.cat_id
					})
				},
				gotoSearch() {
				     uni.navigateTo({
				       url: '/subpkg/search/search'
				     })
				   }
			}
	}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px; 

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title{
	text-align: center;
	padding: 10px 0;
	font-size: 12px;
	font-weight: bold;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
</style>
